I can’t think of any reason, off the top of my head at least. As far as I can tell, there are only advantages to bilingual education.
You will learn two languages, you will learn to function in two languages. You will also learn how to function in those languages at school. That’s a different kind of language use ...
And way of thinking in two languages. It doesn’t mean that it will always be easy.
It partly depends on how much the two languages are offered at school.
If it’s a lot, by that I mean 70-80% in the second language...
we see that the first language may lag in the first years, but it catches up as time progresses.
But different international studies have shown that children are perfectly capable of following bilingual education...
and that they will master the two languages at the end of the day. So it won’t be bad for your Dutch if you attend bilingual education.
We will have to wait for the results of the pilot which is now underway to see what happens exactly.